Neighborhood social vulnerability and disparities in time to kidney cancer surgical treatment and survival in Arizona

BACKGROUND

Hispanics and American Indians (AI) have high kidney cancer incidence and mortality rates in Arizona. This study assessed: (1) whether racial and ethnic minority patients and patients from neighborhoods with high social vulnerability index (SVI) experience a longer time to surgery after clinical diagnosis, and (2) whether time to surgery, race and ethnicity, and SVI are associated with upstaging to pT3/pT4, disease-free survival (DFS), and overall survival (OS).

METHODS

Arizona Cancer Registry (2009-2018) kidney and renal pelvis cases (n = 4592) were analyzed using logistic regression models to assess longer time to surgery and upstaging. Cox-regression hazard models were used to test DFS and OS.

RESULTS

Hispanic and AI patients with T1 tumors had a longer time to surgery than non-Hispanic White patients (median time of 56, 55, and 45 days, respectively). Living in neighborhoods with high (≥75) overall SVI increased odds of a longer time to surgery for cT1a (OR 1.54, 95% CI: 1.02-2.31) and cT2 (OR 2.32, 95% CI: 1.13-4.73). Race and ethnicity were not associated with time to surgery. Among cT1a patients, a longer time to surgery increased odds of upstaging to pT3/pT4 (OR 1.95, 95% CI: 0.99-3.84). A longer time to surgery was associated with PFS (HR 1.52, 95% CI: 1.17-1.99) and OS (HR 1.63, 95% CI: 1.26-2.11). Among patients with cT2 tumor, living in high SVI neighborhoods was associated with worse OS (HR 1.66, 95% CI: 1.07-2.57).

CONCLUSIONS

High social vulnerability was associated with increased time to surgery and poor survival after surgery.

Prostate Cancer Disparities in Metastatic and Treatment Status for Hispanic Americans Based on Country of Origin Compared to Non-Hispanic Whites Using the National Cancer Database

INTRODUCTION

Among Hispanic-American (HA) men, prostatic cancer (PCa) accounts for nearly one-quarter of the total cancer burden. We sought to identify differences in PCa presentation and treatment status for HA subgroups based on country/region of origin.

MATERIAL AND METHODS

Using the National Cancer Database, we identified patients with histologically confirmed prostate adenocarcinoma with reported race/ethnicity, clinical staging, Gleason score ≥ 6, and PSA level at diagnosis from 2010 to 2016. HAs were divided into 4 subgroups: Mexican, Puerto Ricans, Cubans, and Central/South Americans. Non-Hispanic White (NHW) men were used as a reference group. Statistical analysis was derived from the Kruskal-Wallis test for continuous variables and χ2 test for categorical variables. Models were constructed to evaluate the association of Hispanic country of origin with metastatic presentation and treatment status.

RESULTS

A total of 428,829 patients were included, with 5625 (1.3%) classified as HA. Within the Hispanic group, 2880 (51.2%) were Mexican, 999 (17.8%) Puerto Rican, 477 (8.5%) Cuban, and 1269 (22.6%) South/Central American. Mexican men presented with higher median PSA, more Gleason 8 to 10 disease, and higher rates of metastatic presentation compared to NHW and other HA subgroups (all, p < .01). Metastatic rates over the study period for Mexican, Puerto Rican, Cuban, and South/Central Americans were 6.4 (±1.2), 5.3 (±3.0), 3.2 (±2.0), and 4.6% (±1.7), respectively (p = .01). Treatment rates were 89.1, 89.6, 92.4, and 89.3% for Mexican, Puerto Rican, Cuban, and South/Central Americans, respectively (p = .19). Mexican men had higher odds of initial metastatic presentation (OR: 1.32; 95%CI: 1.07-1.63, p = .01) but lower odds of receiving treatment (0.68; 0.55-0.85, p < .01).

CONCLUSION

Men of Mexican origin presented with more advanced PCa when compared to NHW and other Hispanic subgroups. Our results warrant further investigation into potential biological factors affecting Hispanic patients as well as the identification of treatment barriers for this vulnerable population.

Examination of eQTL Polymorphisms Associated with Increased Risk of Progressive Complicated Sarcoidosis in European and African Descent Subjects

Background

A limited pool of SNPs are linked to the development and severity of sarcoidosis, a systemic granulomatous inflammatory disease. By integrating genome-wide association studies (GWAS) data and expression quantitative trait loci (eQTL) single nuclear polymorphisms (SNPs), we aimed to identify novel sarcoidosis SNPs potentially influencing the development of complicated sarcoidosis.

Methods

A GWAS (Affymetrix 6.0) involving 209 African-American (AA) and 193 European-American (EA, 75 and 51 complicated cases respectively) and publicly-available GWAS controls (GAIN) was utilized. Annotation of multi-tissue eQTL SNPs present on the GWAS created a pool of ~46,000 eQTL SNPs examined for association with sarcoidosis risk and severity (Logistic Model, Plink). The most significant EA/AA eQTL SNPs were genotyped in a sarcoidosis validation cohort (n=1034) and cross-validated in two independent GWAS cohorts.

Results

No single GWAS SNP achieved significance (p<1x10-8), however, analysis of the eQTL/GWAS SNP pool yielded 621 eQTL SNPs (p<10-4) associated with 730 genes that highlighted innate immunity, MHC Class II, and allograft rejection pathways with multiple SNPs validated in an independent sarcoidosis cohort (105 SNPs analyzed) (NOTCH4, IL27RA, BTNL2, ANXA11, HLA-DRB1). These studies confirm significant association of eQTL/GWAS SNPs in EAs and AAs with sarcoidosis risk and severity (complicated sarcoidosis) involving HLA region and innate immunity.

Conclusion

Despite the challenge of deciphering the genetic basis for sarcoidosis risk/severity, these results suggest that integrated eQTL/GWAS approaches may identify novel variants/genes and support the contribution of dysregulated innate immune responses to sarcoidosis severity.

Clear cell renal cell carcinoma molecular variations in non-Hispanic White and Hispanic patients

BACKGROUND

The United States is becoming increasingly diverse, but few molecular studies have assessed the progression of clear cell renal cell carcinoma (ccRCC) in diverse patient populations. This study examined ccRCC molecular variations in non-Hispanic White (NHW) and Hispanic patients and their effect on the association of gene expression with high-grade (Grade 3 or 4) ccRCC and overall mortality.

METHODS

A total of 156 patients were included in VHL sequencing and/or TempO-Seq analysis. DESeq2 was used to identify the genes associated with high-grade ccRCC. Logistic regression analysis was performed to assess whether race and ethnicity was associated with high/moderate impact VHL somatic mutations and the ccA/ccB subtype. Cox regression analysis was performed to assess association of molecular subtype and gene expression with overall mortality.

RESULTS

NHWs had moderate or high impact mutations in the VHL gene at a higher frequency than Hispanics (40.2% vs. 27.4%), while Hispanics had a higher frequency of the ccA subtype than NHWs (61.9% vs. 45.8%). ccA was more common in patients with BMI≥35 (65.2%) than in those with BMI < 25 (45.0%). There were 11 differentially expressed genes between high- and low-grade tumors. The Haptoglobin (HP) gene was most significantly overexpressed in high- compared to low-grade ccRCC in all samples (p-adj = 1.7 × 10^-12 ). When stratified by subtype, the 11 genes were significantly differentially expressed in the ccB subtype, but none of them were significant after adjusting for multiple testing in ccA. Finally, patients with the ccB subtype had a significantly increased risk of overall mortality (HR 4.87; p = 0.01) compared to patients with ccA, and patients with high HP expression and ccB, had a significantly increased risk of mortality compared to those with low HP expression and ccA (HR 6.45, p = 0.04).

CONCLUSION

This study reports ccRCC molecular variations in Hispanic patients who were previously underrepresented.

Abstract 1895: Molecular characterization of prostate cancer between Hispanic American and Non-Hispanic Whites: Implications for cancer ethnic health disparities

Background: Although there is increased awareness leading to early detection and prevention, Hispanic American (HA) men with prostate cancer (PC) continue to have greater mortality rates compared to their Non-Hispanic White (NHW) counterparts. Moreover, HA men with PC are more likely to have more advanced disease compared to NHW men. Here, we characterized the molecular and immune differences in HA and NHW tumors and their association with PC ethnic disparity.

Methods: 88 PC samples (HA=34, NHW=54) obtained from treatment-naive metastatic hormone-sensitive PC (mHSPC) were analyzed by next-generation sequencing (592, NextSeq; WES, NovaSeq), Whole Transcriptome Sequencing (WTS; NovaSeq) (Caris Life Sciences, Phoenix, AZ). AR signature and NEPC score were calculated based on the expression level of previously defined genes (Hieronymus et al. 2006, Beltran et al. 2016). Medical record was reviewed in a deidentified fashion for clinal features. Statistical significance was determined using chi-square and Mann-Whitney U (p&lt;0.05).

Results: HA patients with PC had higher level of PSA (111.5 vs 52.6 ng/ml, p=0.12) and stage (T4: 41% vs 14% p=0.01, M1c: 41% vs 16% p=0.04) but no significant difference in frequency of Gleason score &gt; 4 (79% vs 73%, p=0.61) or stage N1 (69% vs 61%, p=0.85) compared to NHW. HA PC had a significantly higher frequency of TMPRSS2-fusion (46.4% vs 20.0%, p=0.04) compared to NHW PC. By Gene Set Enrichment Analysis, HA PC had enrichment of KRAS signaling (NES: 1.44, FDR=0.02), Hedgehog signaling (NES: 1.45, FDR=0.04), NOTCH signaling (NES: 1.41, FDR=0.07), Hypoxia (NES: 1.38, FDR=0.10) and IL2-STAT5 signaling (NES: 1.35, FDR=0.10) pathways compared to NHW tumors. There was no difference in median Androgen Receptor signature (p=0.78) or Neuroendocrine Prostate Cancer (NEPC) score (p=0.79). Also, no significant difference in AR positivity by IHC (100% vs 95.7%) between HA and NHW PC tumors (p=0.51). HA PC had significantly higher expression of stem cell markers ALDH1A1 (2.1-fold), ALDH1A2 (3-fold), and PROM1 (1.6-fold) and immunoinhibitory genes PDCD1LG2 (1.68-fold) and FOXP3 (1.45-fold) compared to NHW tumors (all p&lt;0.05). Additionally, HA tumors had increased infiltration of M1 Macrophages (0.72% vs 0%) and NK cells (4.84% vs 3.55%, all p&lt;0.05), and increased T-cell inflamed score (44.0 vs -49.0, p=0.14) compared to NHW.

Conclusion: Our data suggest that HA mHSPC is associated with higher levels of PSA, stage, TMPRSS2-fusions, stemness marker expression, immunoinhibitory gene expression, and increased M1 Macrophage and NK cell infiltration. Together, these findings suggest a crucial role of differential molecular and tumor immune microenvironment in PC ethnic disparity. A better understanding of these differences with additional research may help in designing the approaches for reducing the ethnic disparities gaps in PC patients.

Citation Format: Alejandro Recio-Boiles, Sachin Kumar Deshmukh, Juan Chipollini, Ken Batai, Sharon Wu, Joanne Xiu, Alex Farrell, Milan Radovich, Elisabeth Heath, Rana McKay, Chadi Nabhan. Molecular characterization of prostate cancer between Hispanic American and Non-Hispanic Whites: Implications for cancer ethnic health disparities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1895.

Genomic profiling between Hispanic Americans (HA) and non-Hispanic (NHW) with advanced prostate cancer: A retrospective analysis of tissue, liquid, and germline testing

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Background: Genomic testing through the employment of somatic and germline testing has become increasingly relevant in determining the prognosis and targeted therapies for advanced prostate cancer patients. Prostate cancer health disparities resulting in worse presentations and clinical outcomes have been observed in HA compared to NHW. Understanding the prevalence of different genomic alterations is paramount to bridge the gap between the two ethnic groups. Methods: This is a retrospective analysis of 190 metastatic prostate adenocarcinoma patients with 24.2% HA who presented to the University of Arizona Cancer Center from 2015 to 2022. Patients in both groups may have undergone more than one type of testing. Homologous recombination repair (HRR) included ATM, BRCA1/2, BARD1, BRIP1, CDK12, CHEK1/2, FANCA/L, HDAC2, PALB2, RAD-51B/1C/51D, or 54L. Tissue-agnostic therapy approvals are dMMR, MSI-H, TMB-High, BRAF V600E, and NTRK/RET fusion. The proportion of HA and NHW was determined, and the statistical significance of the differences was reported using Chi2 or Fisher’s Exact test. Results: 43.6%, 34.7%, and 38.9% of patients had somatic tissue, liquid, and germline testing, respectively analyzed for pathogenic variants. TMB-High >10 (30% vs 3.6%, p=0.02), PD-L1 CPS>5 (9.4% vs 0%, p=0.03) and TMPRSS2-ERG fusion (37.5 vs 7.8%, p=0.0009) had higher proportion in HA compared to NHW. No test showed a difference in BRCA 1/2 or another HRR deficiency actionable mutation between the two ethnicities. There were no other statistically significant differences in common mutations or variants of unknown significance among groups. Conclusions: Liquid and tissue biopsies indicated a difference in proportions for tissue-agnostic and immune-oncology therapeutic indications, being more prevalent in HA. TMPRSS2-ERG fusions have differences in PC development and progression by race and now potentially by ethnicity, as shown by our study. Our review revealed increased germline and somatic testing over time according to targeted therapies approval and guideline recommendations, although, there remains a critical need for advancing genomic sequencing efforts for underrepresented HA. The Hispanic Americans Prostate Cancer Comprehensive Genomic Profiling Study's (THAPCA-GPS) future investigations aim to delineate the pathogenetic differences between HA and NHW and may reduce healthcare disparities and improve clinical outcomes in HA patients. [Table: see text]

Health disparities in metastatic hormone-sensitive prostate cancer (mHSPC) presentations and outcomes among Hispanic Americans (HA) versus non-Hispanic Whites (NHW)

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Background: Multiple retrospective studies conducted have demonstrated disparities in access to care and treatment rates for prostate cancer between HA and NHW. We sought to understand the differences in prostate cancer presenting characteristics, prognosis, and outcomes between the two ethnic groups who presented to the University of Arizona Cancer Center (UACC), which serves a large Hispanic community. Methods: A retrospective analysis of mHSPC adenocarcinoma patients who presented to UACC from 2016 to 2022 was conducted. Patients must have had genetic testing to be included. Patients with no metastasis and incomplete data were excluded. Continuous data were analyzed using t-tests or Wilcoxon Rank sum tests depending on whether they were normally distributed. Categorical variables were analyzed using X2 Tests or Fisher's exact tests. Time to Event data was analyzed using Kaplan-Meier Methods. Results: 83 patients were included with 38.5% HA. No difference was observed between the ethnic groups by median age at presentation (66 years), race (90% white), obesity (40% BMI>30), personal cancer history (10%), or family history of cancer (48%). HA were more likely to have a smoking (69%) and alcohol (63%) history compared to NHW (54% and 39%, respectively; p= 0.04). On presentation, 56% of HA were ECOG 0 compared to 22% of NHW (p=0.001). At the time of diagnosis, HA had median PSA levels of 111.5 ng/ml compared to 52.6 ng/ml in NHW (p=0.12). Gleason Grade Group ≥4 in 73% HA vs 79% in NHW (p=0.61). 41% of HA presented with T4 disease compared to 14% of NHW (p=0.01). 69% of HA presented with N1 disease vs 61% of NHW (p=0.85). 41% of HA presented with visceral metastasis, M1c, compared to 16% of NHW (p=0.04). The median time to first-line (1L) treatment was 1 month in HA compared to 3 months for NHW (p<0.01). 84% of all patients had 1L combination therapy. Abiraterone plus ADT was 1L in 47% of HA compared to 20% of NHW (p=0.06). ADT plus androgen receptor blocker was 1L in 41% of NHW compared to 28% of HA (p=0.06). Median PSA response 3 months after starting treatment was 0.8 ng/ml in HA vs 3.96 ng/ml NHW (p=0.05). The median time to 2L was 20 months for HA vs 11 months in NHW (p=0.05). Conclusions: HA in our study presented with higher PSA, more locally advanced disease, and increased rates of visceral metastases, necessitating a shorter time interval to 1L therapy. HA demonstrated a more favorable response to 1L treatment, noted by lower PSA at 3 months and time to the next line of treatment. Overall survival was not calculated due to the small sample size with only 11 (1 HA vs 10 NHW) total deaths. The Hispanic Americans Prostate Cancer Comprehensive Genomic Profiling Study's (THAPCA-GPS) future investigations aim to delineate the pathogenetic differences between HA and NHW and may reduce healthcare disparities and improve clinical outcomes in HA patients.

Effect Modification of Selenium Supplementation by Intake and Serum Concentrations of Antioxidants on the Development of Metachronous Colorectal Adenoma

BACKGROUND

Selenium (Se) is a trace element that has been investigated as a potential chemopreventive agent for colorectal cancer. Dietary intake of other antioxidant nutrients may modify the effect of Se.

OBJECTIVE

We examined the association between intake and serum concentrations of retinol, β-carotene, β-cryptoxanthin, lycopene, lutein/zeaxanthin, and α- and γ-tocopherol and the development of metachronous colorectal adenoma, and if these nutrients modified the effect of Se.

METHODS

We conducted a prospective study of 1874 participants from the Se Trial with data for antioxidant intake, as well as a subcohort of 508 participants with serum biomarker concentrations.

RESULTS

Statistically significantly lower odds for the development of metachronous adenoma were observed for those participants in the highest tertile of intake for lutein/zeaxanthin compared to the lowest, with an OR (95% CI) of 0.72 (0.56-0.94). No effect modification for intake of any nutrient was observed. However, circulating concentrations of lycopene exhibited statistically significant effect modification of selenium supplementation (p < 0.06).

CONCLUSION

These findings show that intake and circulating concentrations of antioxidant nutrients were not consistently associated with reduced odds for the development of metachronous lesions, although blood concentrations of lycopene may modify the effect of selenium supplementation.

Factors Associated with Cancer Screening Among Hopi Men

Cancer screening rates remain low among American Indian men, and cancer screening behaviors and barriers to cancer screening among American Indian men are not well understood. This study evaluated cancer screening behaviors in 102 Hopi men who were 50 years of age or older from the Hopi Survey of Cancer and Chronic Disease. Reported cancer screening frequencies were 15.7%, 45.1%, and 35.3% for fecal occult blood test (FOBT), colonoscopy, and prostate-specific antigen (PSA) test, respectively. Among men who reported having had a FOBT, 81.2% had the test more than 1 year ago. Among men who reported a colonoscopy, 60.8% had colonoscopy within the past 3 years. Similarly, among men who reported having had PSA, 72.3% had PSA within the past 3 years. "No one told me" was the most common answer for not undergoing FOBT (33.7%), colonoscopy (48.2%), and PSA (39.4%). Men who reported having had a PSA or digital rectal exam were three times as likely to also report having a FOBT or colonoscopy (odds ratio [OR] 3.19, 95% confidence interval [CI]: 1.21-8.46). Younger age (< 65) was associated with reduced odds of ever having prostate cancer screening (OR 0.28, 95% CI: 0.10-0.77). Ever having colorectal cancer screening and previous diagnosis of cancer increased odds of ever having prostate cancer screening (OR 3.15, 95% CI: 1.13-8.81 and OR 5.28, 95% CI: 1.15-24.18 respectively). This study illustrates the importance of community cancer education for men to improve cancer screening participation.

Genome-Wide Association Study of Metachronous Colorectal Adenoma Risk among Participants in the Selenium Trial

Genetic variants related to colorectal adenoma may help identify those who are at highest risk of colorectal cancer development or illuminate potential chemopreventive strategies. The purpose of this genome-wide association study was to identify genetic variants that are associated with risk of developing a metachronous colorectal adenoma among 1,215 study participants of European descent from the Selenium Trial. Associations of variants were assessed with logistic regression analyses and validated in an independent case-control study population of 1,491 participants from the Colorectal Cancer Study of Austria (CORSA). No statistically significant genome-wide associations between any variant and metachronous adenoma were identified after correction for multiple comparisons. However, an intron variant of FAT3 gene, rs61901554, showed a suggestive association (P = 1.10 × 10-6) and was associated with advanced adenomas in CORSA (P = 0.04). Two intronic variants, rs12728998 and rs6699944 in NLRP3 were also observed to have suggestive associations with metachronous lesions (P = 2.00 × 10-6) in the Selenium Trial and were associated with advanced adenoma in CORSA (P = 0.03). Our results provide new areas of investigation for the genetic basis of the development of metachronous colorectal adenoma and support a role for FAT3 involvement in the Wnt/β-catenin pathway leading to colorectal neoplasia.Trial Registration number: NCT00078897 (ClinicalTrials.gov).

Abstract 3665: Clear cell renal cell carcinoma molecular characteristics in Hispanic Americans compared to European Americans

Background: Hispanic Americans (HAs) have higher incidence and mortality rates of renal cell carcinoma (RCC) than European Americans (EAs). Despite the disparate burden of RCC, tumor molecular characteristics among HAs are unknown. This study explored clear cell RCC (ccRCC) molecular difference between HAs and EAs.

Methods: Paraffin embedded surgical specimens of ccRCC patients who underwent nephrectomy for a treatment of RCC were obtained. Three exons of VHL gene were screened for somatic mutations in a total of 150 patients. 96 patients were included for TempO-Seq analysis. A centroid-based approach with 34 gene set was used to assign molecular subtype (ccA or ccB). DESeq2 was used for differential gene expressional analysis.

Results: HAs were younger (mean age of 55.7 vs. 61.2) and had slightly higher mean Body Mass Index (BMI, 32.1 vs. 30.3). More HAs reported that they never smoked (71%) compared to EAs (46%). 73 somatic mutations in coding regions of VHL were found in 56 patients (37.3%), and 11 patients had more than 2 somatic mutations in coding regions. Mutations in coding regions were more common in EAs (41.5%) than HAs (35.5%), but the difference was not statistically significant (p=0.49). When we focused on moderate or high impact mutations, EAs had mutations at higher frequency than HAs (40.2 vs. 27.4%; p=0.07 after adjusting for age and sex). Frequency of somatic mutations was also higher for former (30.3%) and current smokers (40.0%) compared to non-smokers (24.3%). After including smoking history in the regression model, HA ethnicity was not associated with presence of high/moderate impact somatic mutations. HAs had a higher frequency of ccA subtype than EAs (61.9% vs 45.8%). ccA subtype was also more common in patients with BMI&gt;35 (65.2%) than patients with BMI&lt;25 (45.0%). In the adjusted model, HAs had significantly increased odds of having ccA (OR 3.34, 95%CI: 1.17-9.52). Haptoglobin (HP) gene was most significantly over-expressed in high-grade compared to low-grade ccRCC in an analysis including all samples (log2 fold change 4.0, adjusted-p=1.7x10-12). HP was highly over-expressed in high-grade compared to low-grade ccRCC in EAs (log2 fold change 5.2, adjusted-p=4.9x10-9), but not in HA tumors (log2 fold change 2.5, adjusted-p=0.06).

Conclusion: HA and EA tumors have different molecular characteristics potentially due to differences in prevalence of behavioral risk factors.

Impact: Different molecular characteristics in racial/ethnic groups may impact clinical treatment in diverse patient populations.

Citation Format: Ken Batai, Yuliang Chen, Brenna Rheinheimer, Ron Heimark, Nathan Ellis, Benjamin R. Lee. Clear cell renal cell carcinoma molecular characteristics in Hispanic Americans compared to European Americans [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3665.

Disparities in prostate cancer: An ethnicity comparative focus among Hispanic Americans versus non-Hispanic whites

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Background: Prostate cancer (PCa) is a clinically heterogeneous disease and the incidence and mortality risk varies widely among racial/ethnic groups. Among Hispanic American (HA) men, PCa accounts for nearly one-quarter of the total cancer burden; in addition, advanced stage and mortality rates are significantly higher in HA compared to Non-Hispanic White (NHW) men. Despite a decade of declining overall incidence rates, incidence rates of advanced PCa appear to be increasing over time among HA men, a similar pattern seen among Non-Hispanic Blacks (NHB). Methods: Using the National Cancer Database, we identified patients with histologically confirmed prostate adenocarcinoma with reported race/ethnicity, clinical staging, Gleason score ≥ 6, and PSA at diagnosis between 2010 and 2016. HAs were divided into four major subgroups: Mexican/Chicano, Puerto Ricans, Cubans, and Central/South Americans. NHB, Asian, and other racial groups were excluded. Statistical analysis was derived from the Kruskal-Wallis test for continuous variables and χ2 test for categorical variables. Univariable and multivariable logistic regression models were used to evaluate the association of HA ethnic subgroups with metastatic presentation and primary treatment. Results: A total of 428,829 patients were included with 5,625 (1.3%) being HA. Mexican comprised 51.2% of HAs and presented with higher PSA and Gleason score at diagnosis and more advanced cT, N1 and M1 stage when compared to NHW men and other HA subgroups (all, p < 0.001) (Table). After adjusting for age, PSA, year of diagnosis, cT, N, insurance, income, education, and performance score, Mexican had 1.32 (95%CI: 1.07-1.63, p = 0.01) higher odds of initial metastatic presentation and 0.68 (95%CI: 0.55-0.85, p < 0.001) lower odds of receiving treatment compared to NHW men while no statistically significant difference was seen for the other HA subgroups. Conclusions: Even after accounting for socioeconomic disparities, Mexican men present with a more aggressive disease when compared to NHW and other HA subgroups. Our results warrant further investigations into potential biological factors affecting HA PCa as well as identifications of potential barriers to treatment for vulnerable populations.[Table: see text]

Impacts of Neighborhood Characteristics and Surgical Treatment Disparities on Overall Mortality in Stage I Renal Cell Carcinoma Patients

Racial/ethnic minority groups in the United States have high renal cell carcinoma (RCC) mortality rates. This study assessed surgical treatment disparities across racial/ethnic groups and impacts of neighborhood socioeconomic characteristics on surgical treatments and overall mortality. Stage I RCC patients diagnosed between 2004 and 2016 from National Cancer Database were included (n = 238,141). We assessed differences in associations between race/ethnicity and treatment patterns using logistic regression and between race/ethnicity and overall mortality using Cox regression with and without neighborhood characteristics in the regression models. When compared to non-Hispanic Whites (NHWs), American Indians/Alaska Natives and non-Hispanic Blacks (NHBs) were more likely not to receive surgical care and all racial/ethnic minority groups had significantly increased odds of undergoing radical rather than partial nephrectomy, even after adjusting for neighborhood characteristics. Including surgical treatment and neighborhood factors in the models slightly attenuated the association, but NHBs had a significantly increased risk of overall mortality. NHBs who underwent radical nephrectomy had an increased risk of mortality (HR 1.15, 95% CI: 1.08-1.23), but not for NHBs who underwent partial nephrectomy (HR 0.92, 95% CI: 0.84-1.02). Neighborhood factors were associated with surgical treatment patterns and overall mortality in both NHBs and NHWs. Neighborhood socioeconomic factors may only partly explain RCC disparities.

Renal Cell Carcinoma Surgical Treatment Disparities in American Indian/Alaska Natives and Hispanic Americans in Arizona

American Indians/Alaska Natives (AI/AN) and Hispanic Americans (HA) have higher kidney cancer incidence and mortality rates compared to non-Hispanic Whites (NHW). Herein, we describe the disparity in renal cell carcinoma (RCC) surgical treatment for AI/AN and HA and the potential association with mortality in Arizona. A total of 5111 stage I RCC cases diagnosed between 2007 and 2016 from the Arizona Cancer Registry were included. Statistical analyses were performed to test the association of race/ethnicity with surgical treatment pattern and overall mortality, adjusting for patients' demographic, healthcare access, and socioeconomic factors. AI/AN were diagnosed 6 years younger than NHW and were more likely to receive radical rather than partial nephrectomy (OR 1.49 95% CI: 1.07-2.07) compared to NHW. Mexican Americans had increased odds of not undergoing surgical treatment (OR 1.66, 95% CI: 1.08-2.53). Analysis showed that not undergoing surgical treatment and undergoing radical nephrectomy were statistically significantly associated with higher overall mortality (HR 1.82 95% CI: 1.21-2.76 and HR 1.59 95% CI: 1.30-1.95 respectively). Mexican Americans, particularly U.S.-born Mexican Americans, had an increased risk for overall mortality and RCC-specific mortality even after adjusting for neighborhood socioeconomic factors and surgical treatment patterns. Although statistically not significant after adjusting for neighborhood-level socioeconomic factors and surgical treatment patterns, AI/AN had an elevated risk of mortality.

Abstract PO-169: Impacts of neighborhood characteristics and surgical treatment disparities on overall mortality in stage I renal cell carcinoma patients

Background Racial/ethnic minority groups in the United States have high kidney cancer mortality rates. Disparities in treatments may contribute to higher mortality in racial/ethnic minority groups, but the relationship between treatment disparities and kidney cancer mortality is not well understood. In this study, we assessed if there are differences in surgical treatments across racial/ethnic groups and surgical treatments influence disparities in overall mortality. Methods Stage I renal cell carcinoma patients who were diagnosed between 2004 and 2016 from National Cancer Database were included. Logistic regression was performed to assess associations between race/ethnicity and treatment patterns adjusting for neighborhood socioeconomic (SES) and other factors. Cox regression analysis was performed to assess associations between race/ethnicity and overall mortality. Results A total of 238,141 patients were included in the analysis. Compared to non-Hispanic Whites, American Indians/Alaska Natives, and non-Hispanic Blacks (NHBs) were more likely not to receive surgical care even after adjusting for neighborhood SES (OR 1.85, 95% CI: 1.28-2.70 and OR 1.32 95% CI: 1.20-1.45 respectively). Although all racial/ethnic groups had significantly increased odds of undergoing radical nephrectomy rather than partial nephrectomy,. NHBs had the greatest odds of receiving radical rather than partial nephrectomy (OR 1.38, 95% CI: 1.33-1.44).. The associations were slightly attenuated after including healthcare access and neighborhood SESNHBs had an elevated risk of overall mortality, while Asian Americans and Hispanic Americans had reduced risk. Including surgical treatment, health access and neighborhood factors slightly attenuated the association for NHBs, but the associations between race/ethnicity and overall mortality remained significant. Analysis was performed stratifying samples based on surgical treatment to further assess effects of surgical treatment disparities on associations between race/ethnicity and overall mortality. NHBs who had surgical treatment had increased risk of mortality (HR 1.11, 95% CI:1.06-1.17).. Among patients who underwent nephrectomy, NHBs who underwent radical nephrectomy had increased risk of mortality (HR 1.15, 95% CI: 1.08-1.23), but not NHBs who underwent partial nephrectomy (HR 0.92, 95% CI:0.84-1.02). Conclusion Racial/ethnic minority patients were more likely not to receive surgical treatment. When they do, they are likely to have less optimal surgical treatment (radical rather than partial nephrectomy). Surgical treatment disparities account for high kidney cancer mortality in NHBs.

Citation Format: Alejandro Cruz, Faith Dickerson, Kathryn R. Pulling, Kyle Garcia, Francine C. Gachupin, Chiu-Hsieh Hsu, Juan Chipollini, Benjamin R. Lee, Ken Batai. Impacts of neighborhood characteristics and surgical treatment disparities on overall mortality in stage I renal cell carcinoma patients [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-169.

Digital image analysis using video microscopy of human-derived prostate cancer vs normal prostate organoids to assess migratory behavior on extracellular matrix proteins

The advent of perpetuating living organoids derived from patient tissue is a promising avenue for cancer research but is limited by difficulties with precise characterization. In this brief communication, we demonstrate via time-lapse imaging distinct phenotypes of prostate organoids derived from patient material- without confirmation of cellular identity. We show that organoids derived from histologically normal tissue more readily spread on a physiologic extracellular matrix (ECM) than on pathologic ECM (p<0.0001), while tumor-derived organoids spread equally on either substrate (p=0.2406). This study is an important proof-of-concept to defer precise characterization of organoids and still glean information into disease pathology.

Genetic Contributions to Prostate Cancer Disparities in Men of West African Descent

Prostate cancer (PCa) is the second most frequently diagnosed malignancy and the second leading cause of death in men worldwide, after adjusting for age. According to the International Agency for Research on Cancer, continents such as North America and Europe report higher incidence of PCa; however, mortality rates are highest among men of African ancestry in the western, southern, and central regions of Africa and the Caribbean. The American Cancer Society reports, African Americans (AAs), in the United States, have a 1.7 increased incidence and 2.4 times higher mortality rate, compared to European American's (EAs). Hence, early population history in west Africa and the subsequent African Diaspora may play an important role in understanding the global disproportionate burden of PCa shared among Africans and other men of African descent. Nonetheless, disparities involved in diagnosis, treatment, and survival of PCa patients has also been correlated to socioeconomic status, education and access to healthcare. Although recent studies suggest equal PCa treatments yield equal outcomes among patients, data illuminates an unsettling reality of disparities in treatment and care in both, developed and developing countries, especially for men of African descent. Yet, even after adjusting for the effects of the aforementioned factors; racial disparities in mortality rates remain significant. This suggests that molecular and genomic factors may account for much of PCa disparities.

National trends and survival outcomes of penile squamous cell carcinoma based on human papillomavirus status

Background

There are no series evaluating penile squamous cell carcinoma (pSCC) based on human papillomavirus (HPV) infection. Herein, we present national registry data on clinical and survival outcomes for pSCC based on HPV status.

Methods

We performed a retrospective review of 1224 pSCC patients with known HPV staining from the National Cancer Database. Patients with cM1 disease, those who did not receive treatment, or had missing follow‐up data were excluded. Logistic regression identified factors associated with locally aggressive disease. Univariable, multivariable, and inverse probability of treatment weighting (IPTW)‐Cox proportional hazard modeling were used to assess hazard ratios (HR) associated with overall survival (OS).

Results

After exclusion criteria, we identified 825 cases of which 321 (38.9%) were HPV positive. The HPV‐positivity rate did not significantly change by year. HPV‐positive patients were younger, had lower Charlson‐Deyo performance score, and resided in areas with both lower median household income and lower school education completion. HPV‐positive tumors presented with lower American Joint Committee on Cancer clinical T‐stage (cT), poorer differentiation, lower rates of lymphovascular invasion (LVI), but more node‐positive disease (cN+). For those who underwent lymph node surgery, there were no differences in final pathologic stage, upstaging, or presence of extranodal extension. Only tumor differentiation, LVI, and performance score were independent predictors for locally aggressive disease. HPV status was not a predictor of OS (IPTW‐HR:0.89, p = 0.13).

Conclusions

In the largest series evaluating pSCC based on HPV status, HPV‐positive tumors were associated with lower cT stages, less LVI, but more cN + disease. More studies on prognostic factors are needed, and time may still be immature to use HPV information for risk stratification.

Mendelian randomisation and experimental medicine approaches to IL-6 as a drug target in PAH

Background

Inflammation and dysregulated immunity are important in the development of pulmonary arterial hypertension (PAH). Compelling preclinical data supports the therapeutic blockade of interleukin-6 (IL-6) signalling.

Methods

We conducted a phase 2 open-label study of intravenous tocilizumab (8 mg·kg⁻¹) over 6 months in patients with group 1 PAH. Co-primary end-points were safety, defined by incidence and severity of adverse events, and change in pulmonary vascular resistance. Separately, a mendelian randomisation study was undertaken on 11 744 individuals with European ancestry including 2085 patients with idiopathic/heritable disease for the IL-6 receptor (IL6R) variant (rs7529229), known to associate with circulating IL-6R levels.

Results

We recruited 29 patients (male/female 10/19; mean±sd age 54.9±11.4 years). Of these, 19 had heritable/idiopathic PAH and 10 had connective tissue disease-associated PAH. Six were withdrawn prior to drug administration; 23 patients received at least one dose of tocilizumab. Tocilizumab was discontinued in four patients owing to serious adverse events. There were no deaths. Despite evidence of target engagement in plasma IL-6 and C-reactive protein levels, both intention-to-treat and modified intention-to-treat analyses demonstrated no change in pulmonary vascular resistance. Inflammatory markers did not predict treatment response. Mendelian randomisation did not support an effect of the lead IL6R variant on risk of PAH (OR 0.99, p=0.88).

Conclusion

Adverse events were consistent with the known safety profile of tocilizumab. Tocilizumab did not show any consistent treatment effect.

Tocilizumab did not block IL-6 signalling in pulmonary arterial hypertension. Multicentre mendelian randomisation studies additionally did not demonstrate evidence for IL-6R in pulmonary arterial hypertension.https://bit.ly/3xkDxS5

Abstract 2191: Clear cell renal cell carcinoma molecular differences between Hispanic Americans and European Americans

Background: Hispanic Americans (HAs) in Arizona have a heavy burden of renal cell carcinoma (RCC) presenting at a younger age at diagnosis with higher incidence and mortality rates than European Americans (EAs). However, HAs are underrepresented in RCC research, and tumor molecular characteristics in this population are unknown. We report preliminary findings from a study of molecular differences between HAs and EAs exploring the molecular basis of early-onset clear cell RCC (ccRCC).

Methods: Clinical records of patients who underwent surgical treatment for RCC between 2011 and 2020 at the University of Arizona Department of Urology was reviewed. A total of 539 patients were identified, and paraffin embedded surgical specimens of a subset of patients with ccRCC were selected for this study. Three exons of VHL gene, the most commonly altered gene in ccRCC, were screened for somatic mutations in a total of 117 patients. Thirty-three patients were included for TempO-Seq analysis to correlate molecular subtype with demographic and clinicopathologic characteristics.

Results: Among 117 patients, 55 somatic mutations in coding regions of VHL were found in 42 patients (35.9%). Nine patients had more than 2 somatic mutations. There were 37 substitutions, 14 deletions, and 4 insertions. There was one patient with a mutation of an intron variant that was a splice acceptor. Mutations in the coding regions were more common in EAs (40.9%) than HAs (31%), but the difference was not statistically significant (P=0.32). For moderate or high impact mutations, EAs had mutations at a significantly higher frequency than HAs (39.4% vs. 20.5%, P=0.04). Patients with high impact mutations tend to be diagnosed before the age of 50 (37.5%) compared to patients without high impact mutations (23.9%). We were able to assign 32 out of 33 patients into molecular subtypes (ccA and ccB). Molecular subtype could not be assigned to one HA patient with high grade and advanced stage ccRCC. Compared to patients with ccB subtype, patients who had ccA subtype were younger (mean age of 52.2 vs. 61.4) and tend to be obese (55.6% vs. 28.6% body mass index ≥30). Molecular subtype, ccA, was more common in HAs than EAs (64.3% vs. 41.2%), but this difference was not statistically significant.

Conclusion: Somatic mutations within the VHL gene often altered in early during ccRCC pathogenesis were less common in HAs, but ccA associated with early age of diagnosis and obesity was more common in HAs.

Impact: HAs and EAs have different molecular basis of early-onset ccRCC which may impact clinical managements.

Citation Format: Yuliang Chen, Karleen M. Meiklejohn, Nathan Ellis, Erika R. Bracamonte, Benjamin R. Lee, Ken Batai. Clear cell renal cell carcinoma molecular differences between Hispanic Americans and European Americans [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2191.

Correlation between body mass index and prostate volume in benign prostatic hyperplasia patients undergoing holmium enucleation of the prostate surgery

Background

Benign prostatic obstruction (BPO) due to benign prostatic hyperplasia (BPH) is a leading cause of morbidity in men over the age of 40. This study examined whether there was an association between body mass index (BMI) and pre-operative prostate volume and whether expression of two genes, alpha-2-macroglobulin (A2M) and transforming growth factor beta 3 (TGFB3), was correlated with BMI, pre-operative prostate volume, and age at surgery.

Methods

Medical records of patients who underwent holmium enucleation of the prostate surgery for treatment of BPO were retrospectively reviewed. Surgical specimens were obtained from formalin-fixed paraffin-embedded blocks, and expression of the targeted genes was quantified using a real time PCR approach. Linear regression analysis was performed to assess association between BMI and prostate volume adjusting for demographic characteristics and co-morbidity. Spearman’s correlation was used to examine whether gene expression was correlated with BMI, prostate volume, and age at surgery.

Results

A total of 278 patients were identified, including 62.9% European Americans (n = 175) and 27.7% Hispanic Americans (n = 77). BMI was significantly correlated with prostate volume (Spearman’s rho = 0.123, P = 0.045). In linear regression analysis, BMI was positively associated with prostate volume (β = 0.01, P = 0.004), while hyperlipidemia was negatively associated with prostate volume (β = −0.08, P = 0.02). A trend for a positive association was also observed for diabetes (β = 0.07, P = 0.099). In the race/ethnicity stratified analysis, age at surgery showed a trend for significantly positive association with prostate volume in European Americans (β = 0.005, P = 0.08), but not in Hispanic Americans. Expression of the A2M gene in the stroma was negatively correlated with age at surgery (P = 0.006). A2M expression in the gland was positively correlated with prostate volume among older men (Age ≥ 70, P = 0.01) and overweight men (BMI 25–30, P = 0.04). TGFB3 expression in the gland was positively correlated with BMI (P = 0.007) among older men.

Conclusions

This study demonstrated the positive correlation between BMI and prostate volume. Expression of TGFB3 and A2M was correlated with BMI, prostate volume, and age at surgery.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12894-020-00753-9.

Differential DNA Methylation by Hispanic Ethnicity Among Firefighters in the United States

Firefighters are exposed to a variety of environmental hazards and are at increased risk for multiple cancers. There is evidence that risks differ by ethnicity, yet the biological or environmental differences underlying these differences are not known. DNA methylation is one type of epigenetic regulation that is altered in cancers. In this pilot study, we profiled DNA methylation with the Infinium MethylationEPIC in blood leukocytes from 31 Hispanic white and 163 non-Hispanic white firefighters. We compared DNA methylation (1) at 12 xenobiotic metabolizing genes and (2) at all loci on the array (>740 000), adjusting for confounders. Five of the xenobiotic metabolizing genes were differentially methylated at a raw P-value <.05 when comparing the 2 ethnic groups, yet were not statistically significant at a 5% false discovery rate (q-value <.05). In the epigenome-wide analysis, 76 loci exhibited DNA methylation differences at q < .05. Among these, 3 CpG sites in the promoter region of the biotransformation gene SULT1C2 had lower methylation in Hispanic compared to non-Hispanic firefighters. Other differentially methylated loci included genes that have been implicated in carcinogenesis in published studies (FOXK2, GYLTL1B, ZBTB16, ARHGEF10, and more). In this pilot study, we report differential DNA methylation between Hispanic and non-Hispanic firefighters in xenobiotic metabolism genes and other genes with functions related to cancer. Epigenetic susceptibility by ethnicity merits further study as this may alter risk for cancers linked to toxic exposures.

IL-18 mediates sickle cell cardiomyopathy and ventricular arrhythmias

Previous reports indicate that IL18 is a novel candidate gene for diastolic dysfunction in sickle cell disease (SCD)-related cardiomyopathy. We hypothesize that interleukin-18 (IL-18) mediates the development of cardiomyopathy and ventricular tachycardia (VT) in SCD. Compared with control mice, a humanized mouse model of SCD exhibited increased cardiac fibrosis, prolonged duration of action potential, higher VT inducibility in vivo, higher cardiac NF-κB phosphorylation, and higher circulating IL-18 levels, as well as reduced voltage-gated potassium channel expression, which translates to reduced transient outward potassium current (Ito) in isolated cardiomyocytes. Administering IL-18 to isolated mouse hearts resulted in VT originating from the right ventricle and further reduced Ito in SCD mouse cardiomyocytes. Sustained IL-18 inhibition via IL-18-binding protein resulted in decreased cardiac fibrosis and NF-κB phosphorylation, improved diastolic function, normalized electrical remodeling, and attenuated IL-18-mediated VT in SCD mice. Patients with SCD and either myocardial fibrosis or increased QTc displayed greater IL18 gene expression in peripheral blood mononuclear cells (PBMCs), and QTc was strongly correlated with plasma IL-18 levels. PBMC-derived IL18 gene expression was increased in patients who did not survive compared with those who did. IL-18 is a mediator of sickle cell cardiomyopathy and VT in mice and a novel therapeutic target in patients at risk for sudden death.

Genetic loci associated with skin pigmentation in African Americans and their effects on vitamin D deficiency

A recent genome-wide association study (GWAS) in African descent populations identified novel loci associated with skin pigmentation. However, how genomic variations affect skin pigmentation and how these skin pigmentation gene variants affect serum 25(OH) vitamin D variation has not been explored in African Americans (AAs). In order to further understand genetic factors that affect human skin pigmentation and serum 25(OH)D variation, we performed a GWAS for skin pigmentation with 395 AAs and a replication study with 681 AAs. Then, we tested if the identified variants are associated with serum 25(OH) D concentrations in a subset of AAs (n = 591). Skin pigmentation, Melanin Index (M-Index), was measured using a narrow-band reflectometer. Multiple regression analysis was performed to identify variants associated with M-Index and to assess their role in serum 25(OH)D variation adjusting for population stratification and relevant confounding variables. A variant near the SLC24A5 gene (rs2675345) showed the strongest signal of association with M-Index (P = 4.0 x 10-30 in the pooled dataset). Variants in SLC24A5, SLC45A2 and OCA2 together account for a large proportion of skin pigmentation variance (11%). The effects of these variants on M-Index was modified by sex (P for interaction = 0.009). However, West African Ancestry (WAA) also accounts for a large proportion of M-Index variance (23%). M-Index also varies among AAs with high WAA and high Genetic Score calculated from top variants associated with M-Index, suggesting that other unknown genomic factors related to WAA are likely contributing to skin pigmentation variation. M-Index was not associated with serum 25(OH)D concentrations, but the Genetic Score was significantly associated with vitamin D deficiency (serum 25(OH)D levels less than 12 ng/mL) (OR, 1.30; 95% CI, 1.04-1.64). The findings support the hypothesis suggesting that skin pigmentation evolved responding to increased demand for subcutaneous vitamin D synthesis in high latitude environments.

Postoperative and Survival Outcomes After Cytoreductive Surgery in the Treatment of Metastatic Upper Tract Urothelial Carcinoma

OBJECTIVE

To analyze utilization and outcomes of cytoreductive surgery (CRS) after systemic chemotherapy in select patients with metastatic upper tract urothelial carcinoma (UTUC).

MATERIAL AND METHODS

We identified 1,73 patients with cM1 UTUC from the National Cancer Database who were treated with first-line multiagent chemotherapy from 2004 to 2015. Patients considered surgical candidates based on Charlon-Deyo performance score were stratified into nonsurgical versus surgical arms based on receipt of CRS after systemic therapy. Those receiving radiation, immunotherapy, or other types of treatment were excluded. Cox proportional hazard models were used to analyze prognostic factors for overall survival (OS). Propensity-score matching and inverse probability of treatment weighting-adjusted regression models were used to compare OS.

RESULTS

A total of 1182 patients were included of which 349 (29.5%) were treated with definitive surgery. Median follow-up was 64 months (95% confidence interval:49.8-79.4) for chemotherapy+surgery versus 61.2 (52.2-78.7) for the chemotherapy-alone arms (P = .09). Patients treated with surgery were younger and more commonly treated at academic facilities. Patients who received CRS had improved median-OS versus those treated with chemotherapy alone (13.7 vs 10.8 months, log-rank P-value <.001). Predictors of OS were performance score, treatment at academic facility, and performance of CRS. Furthermore, in propensity-score and inverse probability of treatment weighting-adjusted Cox regression analyses, CRS was associated with significant OS benefit (hazard ratios = 0.61, 95% confidence interval:0.49-0.77, and 0.63;0.55-0.72; respectively).

CONCLUSION

We provide a contemporary report on the survival benefit of CRS after treatment with systemic therapy for M1 UTUC patients. Longitudinal studies are needed to evaluate the role of surgery, when feasible, within multidisciplinary approaches for this relatively, rare disease.

Genome-Wide Association Study of Response to Selenium Supplementation and Circulating Selenium Concentrations in Adults of European Descent

BACKGROUND

Selenium (Se) is a trace element that has been linked to many health conditions. Genome-wide association studies (GWAS) have identified variants for blood and toenail Se levels, but no GWAS has been conducted to date on responses to Se supplementation.

OBJECTIVES

A GWAS was performed to identify the single nucleotide polymorphisms (SNPs) associated with changes in Se concentrations after 1 year of supplementation. A GWAS of basal plasma Se concentrations at study entry was conducted to evaluate whether SNPs for Se responses overlap with SNPs for basal Se levels.

METHODS

A total of 428 participants aged 40-80 years of European descent from the Selenium and Celecoxib Trial (Sel/Cel Trial) who received daily supplementation with 200 µg of selenized yeast were included for the GWAS of responses to supplementation. Plasma Se concentrations were measured from blood samples collected at the time of recruitment and after 1 year of supplementation. Linear regression analyses were performed to assess the relationship between each SNP and changes in Se concentrations. We further examined whether the identified SNPs overlapped with those related to basal Se concentrations.

RESULTS

No SNP was significantly associated with changes in Se concentration at a genome-wide significance level. However, rs56856693, located upstream of the NEK6, was nominally associated with changes in Se concentrations after supplementation (P = 4.41 × 10-7), as were 2 additional SNPs, rs11960388 and rs6887869, located in the dimethylglycine dehydrogenase (DMGDH)/betaine-homocysteine S-methyltransferase (BHMT) region (P = 0.01). Alleles of 2 SNPs in the DMGDH/BHMT region associated with greater increases in Se concentrations after supplementation were also strongly associated with higher basal Se concentrations (P = 8.67 × 10-8).

CONCLUSIONS

This first GWAS of responses to Se supplementation in participants of European descent from the Sel/Cel Trial suggests that SNPs in the NEK6 and DMGDH/BHMT regions influence responses to supplementation.

Abstract PO-165: Renal cell carcinoma health disparities in American Indians/Alaska Natives and Hispanic Americans

Background: American Indians/Alaska Natives (AIs/ANs) and United States (U.S.)- born Hispanic Americans (HAs) have higher kidney cancer mortality rates compared to non-Hispanic Whites (NHWs). However, causes for the disparities have not been well understood. The aim of our study was to assess if socioeconomic factors and residence pattern (urban vs. rural) account for renal cell carcinoma (RCC) health disparities in AIs/ANs and HAs focusing on advanced stage (stage III/IV) diagnosis and survival. Methods: RCC patients diagnosed between 2004 and 2015 (n=405, 073) in National Cancer Database (NCDB) and between 2007 and 2016 (n=9,982) in Arizona Cancer Registry (ACR) were analyzed. Logistic regression and Cox regression analysis were performed to ascertain the effect of race/ethnicity on stage at diagnosis and overall survival adjusting for patient’s characteristics, including census tract socioeconomic status (SES), Rural-Urban Continuum Codes (RUCC), and other relevant factors. High school graduate rate, median income (or poverty rate), and unemployment rate was used to measure socioeconomic status. In ACR data, sub- distribution Cox proportional hazards regression was performed to study time to death due to RCC accounting for competing risks. Results: There were a total of 405,073 cases in NCDB and 9,982 cases in ACR. In both NCDB and ACR data, AIs/ANs had significantly increased odds of having advanced stage at diagnosis in unadjusted model (OR 1.20, 95% CI: 1.08-1.33 and OR 1.29, 95% CI: 1.06-1.56 respectively in NCDB and ACR), but the association was not significant after adjusting for patient’s characteristics. In both datasets, Mexican Americans had higher odds of having advanced stage diagnosis compared to NHWs (OR 1.22, 95% CI: 1.11-1.35 and OR 2.02, 95% CI: 1.58-2.58 respectively) even after adjusting for patient’s characteristics, including SES and RUCC. In ACR, advanced stage diagnosis was particularly common in U.S.-born Mexican Americans (49.1%) compared to NHWs (26.4%). AIs/ANs showed increased mortality risk in unadjusted model in both datasets (HR 1.10, 95% CI:1.01-1.20 and HR 1.20, 95% CI: 1.05-1.37 respectively in NCDB and ACR). The association was no longer significant in NCDB after adjusting for patient’s characteristics, while it remained significant in ACR (HR 1.33, 95% CI: 1.03-1.72). In Arizona, Mexican Americans had significantly higher risk of mortality compared to NHWs in both unadjusted and adjusted models (HR 2.46, 95% CI: 2.23-2.72 and HR 2.34, 95% CI: 1.93-2.90). The greatest risk of all-cause and RCC-specific mortality was observed in U.S.-born Mexican Americans (HR 3.21, 95% CI: 2.61-3.98 and sub- distribution HR 2.79, 95% CI: 2.05-3.81). Conclusion: RCC disparities in AIs/ANs is partially explained by neighborhood socioeconomic and residence characteristics, but the neighborhood characteristics did not affect the associations for HAs. Greater RCC health disparities were observed among Mexican Americans in Arizona than the national level.

Citation Format: Celina I. Valencia, Francine C. Gachupin, Chiu-Hsieh Hsu, Juan Chipollini, Benjamin R. Lee, Ken Batai. Renal cell carcinoma health disparities in American Indians/Alaska Natives and Hispanic Americans [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-165.

Leveraging genetic ancestry to study health disparities

Research to understand human genomic variation and its implications in health has great potential to contribute in the reduction of health disparities. Biological anthropology can play important roles in genomics and health disparities research using a biocultural approach. This paper argues that racial/ethnic categories should not be used as a surrogate for sociocultural factors or global genomic clusters in biomedical research or clinical settings, because of the high genetic heterogeneity that exists within traditional racial/ethnic groups. Genetic ancestry is used to show variation in ancestral genomic contributions to recently admixed populations in the United States, such as African Americans and Hispanic/Latino Americans. Genetic ancestry estimates are also used to examine the relationship between ancestry‐related biological and sociocultural factors affecting health disparities. To localize areas of genomes that contribute to health disparities, admixture mapping and genome‐wide association studies (GWAS) are often used. Recent GWAS have identified many genetic variants that are highly differentiated among human populations that are associated with disease risk. Some of these are population‐specific variants. Many of these variants may impact disease risk and help explain a portion of the difference in disease burden among racial/ethnic groups. Genetic ancestry is also of particular interest in precision medicine and disparities in drug efficacy and outcomes. By using genetic ancestry, we can learn about potential biological differences that may contribute to the heterogeneity observed across self‐reported racial groups.

Special Issue: Race reconciled II: Interpreting and communicating biological variation and race in 2021

Genetic Admixture and Survival in Diverse Populations with Pulmonary Arterial Hypertension

Rationale: Limited information is available on racial/ethnic differences in pulmonary arterial hypertension (PAH).Objectives: Determine effects of race/ethnicity and ancestry on mortality and disease outcomes in diverse patients with PAH.Methods: Patients with Group 1 PAH were included from two national registries with genome-wide data and two local cohorts, and further incorporated in a global meta-analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for transplant-free, all-cause mortality in Hispanic patients with non-Hispanic white (NHW) patients as the reference group. Odds ratios (ORs) for inpatient-specific mortality in patients with PAH were also calculated for race/ethnic groups from an additional National Inpatient Sample dataset not included in the meta-analysis.Measurements and Main Results: After covariate adjustment, self-reported Hispanic patients (n = 290) exhibited significantly reduced mortality versus NHW patients (n = 1,970) after global meta-analysis (HR, 0.60 [95% CI, 0.41-0.87]; P = 0.008). Although not significant, increasing Native American genetic ancestry appeared to account for part of the observed mortality benefit (HR, 0.48 [95% CI, 0.23-1.01]; P = 0.053) in the two national registries. Finally, in the National Inpatient Sample, an inpatient mortality benefit was also observed for Hispanic patients (n = 1,524) versus NHW patients (n = 8,829; OR, 0.65 [95% CI, 0.50-0.84]; P = 0.001). An inpatient mortality benefit was observed for Native American patients (n = 185; OR, 0.38 [95% CI, 0.15-0.93]; P = 0.034).Conclusions: This study demonstrates a reproducible survival benefit for Hispanic patients with Group 1 PAH in multiple clinical settings. Our results implicate contributions of genetic ancestry to differential survival in PAH.

Abstract C059: Clinical and molecular profile of renal cell carcinoma in Hispanic Americans, Native Americans, and European Americans

Background: Racial/ethnic minority groups, including Hispanic Americans (HAs) and Native Americans (NAs), have a heavier burden of kidney cancer with a higher incidence and mortality than European Americans (EAs). However, HAs and NAs are under-represented in clinical and molecular genomic studies of renal cell carcinoma (RCC), the most common type of kidney cancer, and clinical and molecular characteristics of RCC among them are also unknown. We investigated variations in clinical and molecular characteristics of RCC patients.

Methods: A total of 284 patients, including 90 HAs (31.6%) and 22 NAs (7.7%), who were diagnosed with RCC and without prior diagnosis of cancer were included to understand the patients' clinical characteristics. A subset of 51 samples were selected to screen for somatic mutations on the VHL gene, and 33 samples were selected for whole-transcriptome sequencing analysis.

Results: Compared to EAs, HA and NA patients were diagnosed with RCC at younger ages (P&lt;0.001). HA had about 5 years younger average age at diagnosis than EAs (55.2 vs. 60.6) and an over 2-fold increased odds of diagnosis before age 60 years (OR 2.50, 95% C.I.: 1.36-4.60). Mean age of diagnosis among NAs was 48.9, and NAs had more than 4-fold higher odds of diagnosis at a younger age (OR 4.12, 95% C.I.: 1.31-12.95). NA patients had higher body mass index than EA patients with 77.3% of NA obese patients. Diabetes was more common in HA (45.6%) and NA (50.0%) patients compared to EA (19.6%) patients. An RCC histologic subtype, clear cell RCC (ccRCC), was more common in HAs and NAs than EAs. Over 90% of HA patients had ccRCC, while only 77.6% of EA patients had ccRCC. HAs had increased odds of diagnosis with ccRCC compared to EAs (OR 2.39, 95% C.I.: 1.01-5.67). Among HAs, older patients were more likely to have advanced-stage RCC diagnosis (OR 7.06, 95% C.I.: 1.46-34.11). HAs who used Spanish as their primary language were more likely to have radical nephrectomy rather than partial nephrectomy (OR 5.13, 95% C.I.: 1.23-21.33). We detected pathogenic somatic mutations on the VHL gene, which is known to cause von Hippel-Lindau syndrome, in 4 patients, and these patients were younger than the patients without these mutations (45.5 vs. 57.1). We were able to assign 32 out of 33 patients into molecular subtypes (ccA and ccB). Molecular subtype could not be assigned to one HA patient with high-grade and advanced-stage ccRCC. Molecular subtype, ccA, was more common in HAs than EAs (64.3% vs. 41.2%), but this difference was not statistically significant. One gene, HABP2, showed evidence of differential expression between HA and EA tumors (PADJ&lt;0.05) and was downregulated in HA tumors with log2 fold change &lt;-2.0.

Conclusion: HA and NA RCC patients had different clinical and molecular characteristics from EA patients.

Impact: As we move toward a precision medicine approach for RCC care, it is necessary to better understand the clinical and molecular characteristics of these underserved HA and NA populations with high kidney cancer burden.

Citation Format: Ken Batai, Alfredo Harb de la Rosa, Francine Gachupin, Elliot Imlaer, Erika R. Bracamonte, Bruce Seligmann, Benjamin R. Lee. Clinical and molecular profile of renal cell carcinoma in Hispanic Americans, Native Americans, and European Americans [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C059.

Characterization of urinary microbiome in patients with bladder cancer: Results from a single-institution, feasibility study

OBJECTIVES

The human microbiome has been linked to the development of several malignancies, but there is scarcity of data on the microbiome of bladder cancer patients. In this study, we analyzed microbial composition and diversity among patients with and without bladder cancer.

MATERIAL AND METHODS

Samples were collected from 38 urothelial carcinoma (UC) patients and 10 noncancer controls from August 2018 to May 2019. DNA was extracted and processed for 16 S ribosomal RNA sequencing. Alpha diversity community characteristics including evenness and richness as well as beta diversity metrics were obtained. Linear discriminant analysis effect size was used to identify microbial components whose sequences were more abundant. Pairwise statistics provided quantitative assessment of significant distributions among groups.

RESULTS

Thirty seven total samples contained high quality sequence data for subsequent analyses and divided into 3 cohorts: control (n = 10), muscle-invasive (n = 15) and superficial UC (n = 12). Control samples had significantly higher species evenness when compared to invasive (P = 0.031) and superficial tumors (P = 0.002). In addition, higher species richness was observed in noncancer versus cancer samples (Faith phylogenetic diversity, P < 0.05). Significantly enriched taxa were found in both control (Bacteroides, Lachnoclostridium, Burkholderiaceae) and cancer samples (Bacteroides and Faecalbacterium).

CONCLUSION

Significantly decreased microbial community diversity was seen in the urine of patients with bladder cancer when compared to a noncancer group. Distinct taxa were noted suggesting unique microbial communities in the urine of bladder cancer patients.

Perioperative outcomes of open vs. robotic radical cystectomy: a nationwide comparative analysis (2008–2014)

Introduction

Radical cystectomy (RC) is a complex procedure with high perioperative morbidity. In an effort to reduce complications, robotic-assisted RC (RARC) has been adopted as a minimally invasive alternative to the open approach (ORC). Herein, we examine post-operative outcomes of the two surgical approaches in the United States (US) using a large all-payer database.

Material and methods

Using International Classification of Disease, ninth revision (ICD-9) codes, patient who underwent RC were captured from National Inpatient Sample (2008–2014). ICD-9 diagnosis and procedure codes were used to identify post-operative complications. Trends in the utilization of RARC were analyzed. Logistic and log-linear regression accounting for hospital sample weights and sampling years were performed to analyze outcomes after adjustment of pertinent covariates.

Results

Of 11,189 patients, 14% underwent RARC. RARC was performed in more teaching hospitals, male patients, those with private insurance, and lower comorbidity score. Performance of RARC steadily increased over the study period (p <0.01). In the last year of the study, 22.8% of cases performed robotically. The weighted average length-of-stay were 10.4 and 8.79 days for ORC and RARC, respectively (p <0.01). In multivariable analyses, RARC was associated with decreased blood transfusion, parenteral nutrition, pneumonia, surgical-site infection, wound and respiratory complications (all, p <0.05). No significant differences were found for in-hospital mortality, cardiac, genitourinary, and vascular complications.

Conclusions

Performance of RARC has significantly increased in recent years. RARC appears safe and feasible for select patients. Earlier discharge and lower complications were noted for those undergoing RARC across different hospital systems nationwide.

Racial/ethnic disparities in renal cell carcinoma: Increased risk of early-onset and variation in histologic subtypes

Background

Racial/ethnic minority groups have a higher burden of renal cell carcinoma (RCC), but RCC among Hispanic Americans (HAs) and American Indians and Alaska Natives (AIs/ANs) are clinically not well characterized. We explored variations in age at diagnosis and frequencies of RCC histologic subtypes across racial/ethnic groups and Hispanic subgroups using National Cancer Database (NCDB) and Arizona Cancer Registry Data.

Methods

Adult RCC cases with known race/ethnicity were included. Logistic regression analysis was performed to estimate odds and 95% confidence interval (CI) of early‐onset (age at diagnosis <50 years) and diagnosis with clear cell RCC (ccRCC) or papillary RCC.

Results

A total of 405 073 RCC cases from NCDB and 9751 cases from ACR were identified and included. In both datasets, patients from racial/ethnic minority groups had a younger age at diagnosis than non‐Hispanic White (NHW) patients. In the NCDB, AIs/ANs had twofold increased odds (OR, 2.21; 95% CI, 1.88‐2.59) of early‐onset RCC compared with NHWs. HAs also had twofold increased odds of early‐onset RCC (OR, 2.14; 95% CI, 1.79‐2.55) in the ACR. In NCDB, ccRCC was more prevalent in AIs (86.3%) and Mexican Americans (83.5%) than NHWs (72.5%). AIs/ANs had twofold increased odds of diagnosis with ccRCC (OR, 2.18; 95% CI, 1.85‐2.58) in the NCDB, but the association was stronger in the ACR (OR, 2.83; 95% CI, 2.08‐3.85). Similarly, Mexican Americans had significantly increased odds of diagnosis with ccRCC (OR, 2.00; 95% CI, 1.78‐2.23) in the NCDB.

Conclusions

This study reports younger age at diagnosis and higher frequencies of ccRCC histologic subtype in AIs/ANs and Hispanic subgroups. These variations across racial/ethnic groups and Hispanic subgroups may have potential clinical implications.

Patterns of Cancer Related Health Disparities in Arizona

Cancer incidence rates vary regionally among American Indians (AIs) and Latinos. The goal of this was to identify areas of research necessary to reduce cancer health disparities in AIs and Latinos, the two major racial/ethnic minority groups in Arizona. In an effort to better understand cancer health disparities, cancer incidence rates in AIs and Latinos in Arizona were compared to non-Hispanic Whites (NHWs). Age-adjusted incidence rates (per 100,000) were obtained from the Arizona Cancer Registry and the North American Association of Central Cancer Registries. Spearman's rank test was used to examine correlation between county-level cancer incidence rates and socio-demographic factors. AIs and Latinos had lower incidence rates of screening for detectable cancers than NHWs. Among older men (age ≥65), however, AIs and Latinos had similar prostate cancer incidence rates to NHWs. Some of less common cancers, such as kidney, stomach, liver, and gallbladder, were more frequently diagnosed in AIs and Latinos than NHWs. AIs and Latinos were more likely to be diagnosed with advanced cancer stage, except for cervical cancer. Correlations between prostate and breast cancer incidence rates and percent urban residents as well as correlations between incidence rates of these two cancer types and population size were significantly positive. Poverty levels were inversely correlated with colorectal and lung cancer incidence rates. Our review of cancer incidence rates suggests that socio-demographic factors, such as population size (rural/urban) and poverty levels, have influenced cancer detection and incidence rates in Arizona.

Selenium supplementation and insulin resistance in a randomized, clinical trial

OBJECTIVE

While controversial, observational and randomized clinical trial data implicate the micronutrient selenium (Se) in the development of type 2 diabetes (T2D). The aim of this study was to test the hypothesis that Se supplementation adversely affects pancreatic β-cell function and insulin sensitivity.

RESEARCH DESIGN AND METHODS

In a subset of 400 individuals participating in a randomized, placebo-controlled trial of Se at 200 µg/day for colorectal adenomatous polyps, fasting plasma glucose and insulin were measured before randomization and within 6 months of completing intervention. Change in the homeostasis model assessment-β cell function (HOMA2-%β) and insulin sensitivity (HOMA2-%S) were compared between arms. A subgroup of 175 (79 Se and 96 placebo) participants underwent a modified oral glucose tolerance test (mOGTT) at the end of intervention and change in glucose values was assessed.

RESULTS

No statistically significant differences were observed for changes in HOMA2-%β or HOMA2-%S between those who received Se compared with placebo. After a mean of 2.9 years on study, mean HOMA2-%β values were 3.1±24.0 and 3.1±29.8 for the Se and placebo groups, respectively (p=0.99). For HOMA2-%S, the values were -0.5±223.2 and 80.9±1530.9 for the Se and placebo groups, respectively (p=1.00). Stratification by sex or age did not reveal any statistically significant effects on insulin sensitivity by treatment group. For mOGTT, mean baseline fasting blood glucose concentrations were significantly higher among participants in the placebo group compared with the Se group (96.6±14.6 and 92.3±12.0, respectively; p=0.04), a trend which remained through the 20 min assessment.

CONCLUSIONS

These findings do not support a significant adverse effect of daily Se supplementation with 200 µg/day of selenized yeast on β-cell function or insulin sensitivity as an explanation for previously reported associations between Se and T2D. Further clarification of longer term effects of Se is needed.

CLINICAL TRIAL REGISTRY

NIH Clinical Trials.gov number NCT00078897.

Selenium and Type 2 Diabetes: Systematic Review

Several studies have investigated the potential role of selenium (Se) in the development of type 2 diabetes (T2D) with disparate findings. We conducted a systematic review and meta-analysis to synthesize the evidence of any association between Se and T2D. PubMed, Embase, and Scopus were searched following the Preferred Reporting Items for Systematic Reviews and Meta-analysis Approach (PRISMA). Sixteen studies from 15 papers met inclusion criteria defined for this review. Of the 13 observational studies included, 8 demonstrated a statistically significant positive association between concentrations of Se and odds for T2D, with odds ratios (95% confidence intervals) ranging from 1.52 (1.01–2.28) to 7.64 (3.34–17.46), and a summary odds ratio (OR) (95% confidence interval (CI)) of 2.03 (1.51–2.72). In contrast, among randomized clinical trials (RCTs) of Se, a higher risk of T2D was not observed for those who received Se compared to a placebo (OR = 1.18, 95% CI 0.95–1.47). Taken together, the results for the relationship between Se and T2D differ between observational studies and randomized clinical trials (RCTs). It remains unclear whether these differences are the result of uncontrolled confounding in the observational studies, or whether there is a modest effect of Se on the risk for T2D that may vary by duration of exposure. Further investigations on the effects of Se on glucose metabolism are needed.

Whole-transcriptome sequencing identified gene expression signatures associated with aggressive clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most prevalent subtype of kidney cancer, yet molecular biomarkers have not been used for the prognosis of ccRCC to aide clinical decision making. This study aimed to identify genes associated with ccRCC aggressiveness and overall survival (OS). Samples of ccRCC tumor tissue were obtained from 33 patients who underwent nephrectomy. Gene expression was determined using whole-transcriptome sequencing. The Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma (TCGA-KIRC) RNA-seq data was used to test association with OS. 290 genes were differentially expressed between tumors with high and low stage, size, grade, and necrosis (SSIGN) score (≥7 vs. ≤3) with P_ADJ<0.05. Four genes, G6PD, APLP1, GCNT3, and PLPP2, were also over-expressed in advanced stage (III and IV) and high grade (3 and 4) ccRCC and tumor with necrosis (P_ADJ<0.05). Investigation stratifying by stage found that APLP1 and PLPP2 overexpression were significantly associated with poorer OS in the early stage (Quartile 1 vs. Quartile 4, HR = 3.87, 95% CI:1.25-11.97, P = 0.02 and HR = 4.77, 95% CI:1.37-16.57, P = 0.04 respectively). These genes are potential biomarkers of ccRCC aggressiveness and prognosis that direct clinical and surgical management.

Racial and Ethnic Disparities in Renal Cell Carcinoma: An Analysis of Clinical Characteristics

BACKGROUND

Racial/ethnic minority groups, including Hispanic Americans (HAs) and Native Americans (NAs), have a heavier burden of kidney cancer than European Americans (EAs). We investigated variations in clinical characteristics of HA and NA patients with renal cell carcinoma (RCC) who were previously underrepresented.

MATERIALS AND METHODS

Clinical records of 294 patients with RCC (151 EAs, 95 HAs, 22 NAs, and 26 others) without prior diagnosis of cancer were reviewed. Logistic regression analysis was performed to understand patients' clinical characteristics.

RESULTS

HAs had about 5 years younger average age at diagnosis than EAs (55.8 vs. 60.5 years) and an almost 3-fold increased odds of diagnosis before age 50 years (odds ratio [OR], 2.77; 95% confidence interval [CI], 1.39-5.54). The mean age of diagnosis among NAs was 49.7 years, and NAs had an over 6-fold higher odds of diagnosis at a younger age (OR, 6.23; 95% CI, 2.00-19.46). Clear-cell RCC (ccRCC) was more common in HAs and NAs than EAs. Over 90% of HA patients had ccRCC, whereas only 78.8% of EA patients had ccRCC. HAs had increased odds of diagnosis with ccRCC compared with EAs (OR, 2.79; 95% CI, 1.15-6.80). Among HAs, older patients and patients who spoke Spanish as their primary language were more likely to have advanced stage RCC at diagnosis (OR, 10.48; 95% CI, 1.69-64.89 and OR, 4.61; 95% CI, 1.38-15.40).

CONCLUSION

HA and NA patients with RCC had different clinical characteristics than EA patients. It is necessary to better understand the clinical characteristics of these underserved HA and NA populations with high kidney cancer burden.

Higher Plasma Selenium Concentrations Are Associated with Increased Odds of Prevalent Type 2 Diabetes

Background

Selenium, an essential trace element, has been investigated as a potential cancer prevention agent. However, several studies have indicated that selenium supplementation may be associated with an increased risk of type 2 diabetes (T2D), although an equivocal relation of this nature requires confirmation.

Objective

We examined the association between baseline plasma concentrations of selenium and the prevalence of T2D, as well as whether participant characteristics or intake of other antioxidant nutrients modified this relation.

Methods

We conducted cross-sectional analyses of 1727 participants from the Selenium Trial, a randomized clinical trial of selenium supplementation for colorectal adenoma chemoprevention that had data for baseline selenium plasma concentrations, T2D status, and dietary intake. Logistic regression modeling was used to evaluate the associations between plasma selenium concentrations and prevalent T2D, adjusting for confounding factors. Heterogeneity of effect by participant characteristics was evaluated utilizing likelihood-ratio tests.

Results

Mean ± SD plasma selenium concentrations for those with T2D compared with those without T2D were 143.6 ± 28.9 and 138.7 ± 27.2 ng/mL, respectively. After adjustment for confounding, higher plasma selenium concentrations were associated with a higher prevalence of T2D, with ORs (95% CIs) of 1.25 (0.80, 1.95) and 1.77 (1.16, 2.71) for the second and third tertiles of plasma selenium, respectively, compared with the lowest tertile (P-trend = 0.007). No significant effect modification was observed for age, sex, body mass index, smoking, or ethnicity. Increased odds of T2D were seen among those who were in the highest tertile of plasma selenium and the highest category of intake of β-cryptoxanthin (P-trend = 0.03) and lycopene (P-trend = 0.008); however, interaction terms were not significant.

Conclusions

These findings show that higher plasma concentrations of selenium were significantly associated with prevalent T2D among participants in a selenium supplementation trial. Future work is needed to elucidate whether there are individual characteristics, such as blood concentrations of other antioxidants, which may influence this relation.

Genome-Wide Association Study in African Americans with Acute Respiratory Distress Syndrome Identifies the Selectin P Ligand Gene as a Risk Factor

RATIONALE

Genetic factors are involved in acute respiratory distress syndrome (ARDS) susceptibility. Identification of novel candidate genes associated with increased risk and severity will improve our understanding of ARDS pathophysiology and enhance efforts to develop novel preventive and therapeutic approaches.

OBJECTIVES

To identify genetic susceptibility targets for ARDS.

METHODS

A genome-wide association study was performed on 232 African American patients with ARDS and 162 at-risk control subjects. The Identify Candidate Causal SNPs and Pathways platform was used to infer the association of known gene sets with the top prioritized intragenic SNPs. Preclinical validation of SELPLG (selectin P ligand gene) was performed using mouse models of LPS- and ventilator-induced lung injury. Exonic variation within SELPLG distinguishing patients with ARDS from sepsis control subjects was confirmed in an independent cohort.

MEASUREMENTS AND MAIN RESULTS

Pathway prioritization analysis identified a nonsynonymous coding SNP (rs2228315) within SELPLG, encoding P-selectin glycoprotein ligand 1, to be associated with increased susceptibility. In an independent cohort, two exonic SELPLG SNPs were significantly associated with ARDS susceptibility. Additional support for SELPLG as an ARDS candidate gene was derived from preclinical ARDS models where SELPLG gene expression in lung tissues was significantly increased in both ventilator-induced (twofold increase) and LPS-induced (5.7-fold increase) murine lung injury models compared with controls. Furthermore, Selplg-/- mice exhibited significantly reduced LPS-induced inflammatory lung injury compared with wild-type C57/B6 mice. Finally, an antibody that neutralizes P-selectin glycoprotein ligand 1 significantly attenuated LPS-induced lung inflammation.

CONCLUSIONS

These findings identify SELPLG as a novel ARDS susceptibility gene among individuals of European and African descent.

Clinical and Molecular Characteristics and Burden of Kidney Cancer Among Hispanics and Native Americans: Steps Toward Precision Medicine

Cancer disparities in Native Americans (NAs) and Hispanic Americans (HAs) vary significantly in terms of cancer incidence and mortality rates across geographic regions. This review reports that kidney and renal pelvis cancers are unevenly affecting HAs and NAs compared to European Americans of non-Hispanic origin, and that currently there is significant need for improved data and reporting to be able to advance toward genomic-based precision medicine for the assessment of such cancers in these medically underserved populations. More specifically, in states along the US-Mexico border, HAs and NAs have higher kidney cancer incidence rates as well as a higher prevalence of kidney cancer risk factors, including obesity and chronic kidney disease. They are also more likely to receive suboptimal care compared to European Americans. Furthermore, they are underrepresented in epidemiologic, clinical, and molecular genomic studies of kidney cancer. Therefore, we maintain that progress in precision medicine for kidney cancer care requires an understanding of various factors among HAs and NAs, including the real kidney cancer burden, variations in clinical care, issues related to access to care, and specific clinical and molecular characteristics.

Abstract 1278: Effect modifications of vitamin D receptor common polymorphisms association with prostate cancer by serum vitamin D related behavioral and biological factors

Background: Several roles have been proposed for vitamin D and the vitamin D receptor (VDR) in prostate cancer (PCa) pathogenesis and progression. However, previous genetic epidemiologic studies have provided limited support linking VDR polymorphisms to PCa due to complexity of vitamin D metabolism and potential gene and environmental interactions. In this study, we investigated the association of VDR genotypes with PCa incidence and aggressiveness in African Americans (AAs) and European Americans (EAs) and if the associations were modified by behavioral and biological factors that influence serum vitamin D levels.

Methods: The total of 810 AAs and 487 EAs from Chicago, IL and Washington, D.C. were included in this study. Seven single-nucleotide polymorphisms (SNPs) in and around the VDR gene and 105 ancestry informative markers were genotyped. We performed logistic regression analyses adjusting for relevant variables.

Results: In EAs, TaqI (rs73136) and BsmI (rs1544410) minor alleles revealed a protective effect against PCa, while in AAs, FokI (rs2228570) was associated with overall PCa risk (OR=0.74, 95% C.I.: 0.57-0.96). The heterogeneous associations observed in our study could be due to difference in prevalence of vitamin D deficiency between AAs and EAS and effect modifications by behavioral and biological factors that affect serum vitamin D levels. Therefore, we investigated if behavioral and biological factors that influence serum vitamin D modified the associations between VDR polymorphisms and PCa, and we found evidence suggesting that these behavioral and biological factors modify the effect of VDR on PCa. In AAs, we observed statistically significant interaction between two VDR polymorphisms, FokI and TaqI, and vitamin D intake (PInteraction=0.01 and PInteraction=0.03 respectively). We also observed evidence of interactions between VDR gene variants and other behavioral and biological factors that lower serum vitamin D levels in both AAs and EAs. In AAs, calcium intake and skin pigmentation may modify the effects of VDR on PCa. In EAs, BMI may modify the effect of VDR.

Conclusions: Although a larger sample size is necessary to confirm the observation, we demonstrated that vitamin D related behavioral and biological factors modify the effect of VDR genotypes on PCa. Impact: The VDR gene is involved in PCa pathogenesis and progression, and polymorphisms in VDR gene and vitamin D are likely to alter the function of the gene.

Citation Format: Ken Batai, Adam B. Murphy, Ebony Shah, Chiledum Ahaghotu, Rick A. Kittles. Effect modifications of vitamin D receptor common polymorphisms association with prostate cancer by serum vitamin D related behavioral and biological factors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1278. doi:10.1158/1538-7445.AM2017-1278

Prostatic compensation of the vitamin D axis in African American men

BACKGROUND. African American (AA) men are disproportionately affected by both prostate cancer (PCa) and vitamin D deficiency compared with European American (EA) men. Vitamin D deficiency is linked to increased PCa aggressiveness and mortality. Therefore, it has been hypothesized that vitamin D deficiency may contribute to the PCa disparity between AA and EA men. METHODS. We studied a cross sectional group of 60 PCa patients (AA, n = 31; EA, n = 29) who underwent radical prostatectomy. Vitamin D metabolites 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)₂D) were measured in the serum and tissue by uHPLC-MS-MS. Tissue was laser capture microdissected, and gene expression was quantified by microarray. DNA isolated from whole blood was genotyped for West African ancestry markers and vitamin D-related SNPs. RESULTS. Serum concentrations of 25(OH)D were lower in AAs, but concentrations of 1,25(OH)₂D in the prostate tissue were higher compared with EAs. Expression of the vitamin D receptor was higher in prostate tissue from AAs. Expression of the extracellular receptor of vitamin D binding protein, LRP2, was positively associated with West African ancestry and inversely associated with tissue 25(OH)D concentrations in AAs. CONCLUSIONS. The relationships between vitamin D binding protein LRP2 and vitamin D metabolites suggest that the prohormone is actively transported into the prostate, followed by intraprostatic conversion to the active hormone, rather than passive diffusion. These findings support the presence of a compensatory response in prostate tissue to vitamin D deficiency in AAs and reveal a previously unknown complexity involving tissue distribution of vitamin D metabolites. FUNDING. Department of Defense Prostate Cancer Research Program Idea Award for Disparities Research PC121923 (LN and RK) and the NIH 1R01MD007105 (RK).

Race and BMI modify associations of calcium and vitamin D intake with prostate cancer

BACKGROUND

African Americans have disproportionately higher burden of prostate cancer compared to European Americans. However, the cause of prostate cancer disparities is still unclear. Several roles have been proposed for calcium and vitamin D in prostate cancer pathogenesis and progression, but epidemiologic studies have been conducted mainly in European descent populations. Here we investigated the association of calcium and vitamin D intake with prostate cancer in multiethnic samples.

METHODS

A total of 1,657 prostate cancer patients who underwent screening and healthy controls (888 African Americans, 620 European Americans, 111 Hispanic Americans, and 38 others) from Chicago, IL and Washington, D.C. were included in this study. Calcium and vitamin D intake were evaluated using food frequency questionnaire. We performed unconditional logistic regression analyses adjusting for relevant variables.

RESULTS

In the pooled data set, high calcium intake was significantly associated with higher odds for aggressive prostate cancer (OR_{Quartile 1 vs. Quartile 4} = 1.98, 95% C.I.: 1.01-3.91), while high vitamin D intake was associated with lower odds of aggressive prostate cancer (OR_{Quartile 1 vs. Quartile 4} = 0.38, 95% C.I.: 0.18-0.79). In African Americans, the association between high calcium intake and aggressive prostate cancer was statistically significant (OR_{Quartile 1 vs. Quartile 4} = 4.28, 95% C.I.: 1.70-10.80). We also observed a strong inverse association between total vitamin D intake and prostate cancer in African Americans (OR_{Quartile 1 vs. Quartile 4} = 0.06, 95% C.I.: 0.02-0.54). In European Americas, we did not observe any significant associations between either calcium or vitamin D intake and prostate cancer. In analyses stratifying participants based on Body Mass Index (BMI), we observed a strong positive association between calcium and aggressive prostate cancer and a strong inverse association between vitamin D intake and aggressive prostate cancer among men with low BMI (<27.8 kg/m²), but not among men with high BMI (≥27.8 kg/m²). Interactions of race and BMI with vitamin D intake were significant (P _Interaction < 0.05).

CONCLUSION

Calcium intake was positively associated with aggressive prostate cancer, while vitamin D intake exhibited an inverse relationship. However, these associations varied by race/ethnicity and BMI. The findings from this study may help develop better prostate cancer prevention and management strategies.

Association between Serum 25-Hydroxy-Vitamin D and Aggressive Prostate Cancer in African American Men

African American men have higher incidence rates of aggressive prostate cancer, where high levels of calcium and serum vitamin D deficient levels play a role in the racial differences in incidence. In this study, we examined associations of serum vitamin D with aggressive prostate cancer to improve our understanding of higher susceptibility of aggressive disease in this racial cohort. From Howard University Hospital, 155 African American men with clinically-identified prostate cancer were identified; 46 aggressive cases, and 58 non-aggressive cases. Serum vitamin D was assessed from fasting blood samples, and total calcium intake was assessed using the Block Food Frequency Questionnaire. Vitamin D receptor polymorphisms from three different loci were genotyped; rs731236, rs1544410, and rs11568820. Multivariate logistic regression models were used to determine odds ratios (OR) and 95% confidence intervals (CI) comparing aggressive to non-aggressive prostate cancer. Vitamin D deficiency (<20 ng/mL) significantly increased risk of aggressive disease (OR: 3.1, 95% CI: 1.03–9.57, p-value = 0.04). Stratification by total calcium showed high calcium levels (≥800 mg/day) modified this association (OR: 7.3, 95% CI: 2.15–47.68, p-interaction = 0.03). Genetic variant rs11568820 appeared to increase the magnitude of association between deficient serum vitamin D and aggressive prostate cancer (OR: 3.64, 95% CI: 1.12–11.75, p-value = 0.05). These findings suggest that high incidence of aggressive prostate cancer risk in African American men may be due in-part to deficient levels of serum vitamin D. Other factors, including genetics, should be considered for future studies.

Zinc Intake and Risk of Prostate Cancer: Case-Control Study and Meta-Analysis

Zinc is an essential dietary element that has been implicated in the pathogenesis of prostate cancer, a cancer that disproportionately affects men of African descent. Studies assessing the association of zinc intake and prostate cancer have yielded inconsistent results. Furthermore, very little is known about the relationship between zinc intake and prostate cancer among African Americans. We examined the association between self-reported zinc intake and prostate cancer in a hospital-based case-control study of African Americans. We then compared our results with previous studies by performing a meta-analysis to summarize the evidence regarding the association between zinc and prostate cancer. Newly diagnosed African American men with histologically confirmed prostate cancer (n = 127) and controls (n = 81) were recruited from an urban academic urology clinic in Washington, DC. Controls had higher zinc intake, with a mean of 14 mg/day versus 11 mg/day for cases. We observed a non-significant, non-linear increase in prostate cancer when comparing tertiles of zinc intake (OR <6.5 vs 6.5-12.5mg/day 1.8, 95% CI: 0.6,5.6; OR <6.5 vs >12.5mg/day 1.3, 95% CI: 0.2,6.5). The pooled estimate from 17 studies (including 3 cohorts, 2 nested case-control, 11 case-control studies, and 1 randomized clinical trial, with a total of 111,199 participants and 11,689 cases of prostate cancer) was 1.07hi vs lo 95% CI: 0.98-1.16. Using a dose-response meta-analysis, we observed a non-linear trend in the relationship between zinc intake and prostate cancer (p for nonlinearity = 0.0022). This is the first study to examine the relationship between zinc intake in black men and risk of prostate cancer and systematically evaluate available epidemiologic evidence about the magnitude of the relationship between zinc intake and prostate cancer. Despite of the lower intake of zinc by prostate cancer patients, our meta-analysis indicated that there is no evidence for an association between zinc intake and prostate cancer.

Abstract C32: Native American genetic ancestry is protective against prostate cancer in African Americans and European Americans

Prostate cancer (PCa) incidence and mortality varies by racial/ethnic groups in the U.S. African American (AA) men have a 60% higher incidence and twice the mortality rate of European America (EA) men, while Hispanic Americans and Native Americans have lower incidence rates than EA men. Several genetic admixture studies have examined the role of west African ancestry on prostate cancer risk in AA men, however the influence of Native American ancestry on PCa risk has not been explored. Here we evaluated the relationship between individual genetic ancestry proportions and the likelihood of PCa diagnosis and aggressiveness.

Methods: We recruited 40-79 year old men who were undergoing prostate biopsy or routine PSA screening at outpatient urology clinics in Chicago, IL. Blood was drawn at the time of enrollment for genotyping of 105 ancestry informative markers. West African, European, and Native American genetic ancestry was estimated using the Bayesian Markov Chain-Monte Carlo method implemented in the program STRUCTURE. Unconditional binary logistic regression models were used to estimate odds ratios for the likelihood of PCa diagnosis and for the likelihood of having high-risk PCa relative to controls, adjusting for age and family history of PCa.

Results: In AAs, NAA ranged from 0.4% to 28.8%. Mean NAA was 4.6% in AA cases, while controls had mean NAA of 6.6%. NAA ranged from 0.5% to 17.4% in EAs. Mean NAA was 5.1% in cases and 6.8% in controls. NAA was negatively associated with PCa diagnosis. AA men in the highest quartile of NAA had significantly reduced odds of PCa diagnosis compared to men in the lowest quartile of NAA (OR 0.47, 95% C.I.: 0.29-0.77). Similarly, EA men in the highest quartile of NAA had significantly reduced odds of PCa diagnosis compared men in the lowest NAA quartile (OR 0.36, 95% C.I.: 0.21-0.61). Additional adjustment of body mass index, education, smoking, alcohol use, and marital status did not change the results. NAA was also negatively associated with diagnosis of high risk PCa in EAs (P=0.04) and also trending in the same direction in AAs however not significant.

Conclusions: Our study reveals that NAA is protective against PCa diagnosis and high-risk PCa. Hispanic Americans and Native Americans have lower PCa incidence rates than AAs and EAs, and the identification of inherited genetic or environmental factors that are associated with high NAA may improve PCa risk prediction and/or help to develop prevention strategies.

Citation Format: Adam Murphy, Ken Batai, Ebony Shah, Rick A. Kittles. Native American genetic ancestry is protective against prostate cancer in African Americans and European Americans. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C32.

Abstract B39: Effect modifiers of vitamin D receptor common polymorphisms on prostate cancer risk

Background: Studies have long proposed the influence of vitamin D and the vitamin D receptor (VDR) on prostate cancer (PCa) initiation and progression, however few studies support the association of VDR variants with PCa. The VDR is a transcription factor which binds to vitamin D and influences the expression of many genes implicated in Pca. Given the complexity of vitamin D availability, we hypothesized that the associations of VDR single-nucleotide polymorphisms (SNPs) with PCa can be modified by various behavioral and biological factors. In this study, we examined VDR SNPs and PCa risk and aggressiveness in African Americans (AAs) and European Americans (EAs) and determined if the associations were modified by behavioral and biological factors that influence serum vitamin D levels, including vitamin D and calcium intake, tobacco use, body mass index (BMI), skin pigmentation, and ultraviolet radiation exposure.

Methods: The total of 810 AAs and 487 EAs from Chicago, IL and Washington, D.C. were included. Seven SNPs in and around the VDR gene and 105 ancestry informative markers were genotyped. We performed logistic regression analyses adjusting for relevant variables.

Results: In EAs, TaqI (rs73136) and BsmI (rs1544410) minor alleles (respectively C and A allele) revealed a protective effect against PCa, while BsmI AA genotype showed increased odds of having high grade PCa (Gleason Score ≥4+3) in AAs with OR=2.67 (95% C.I.: 1.01-7.11). We also observed evidence of interactions between VDR SNPs and behavioral and biological factors that modify serum vitamin D levels. The TaqI C allele increased odds of PCa in AAs with behavioral and biological factors that reduce serum vitamin D levels, such as low vitamin D intake, current or past tobacco use, and darker skin pigmentation. Among AA men with vitamin D intake &lt;400 IU/day, the TaqI CT/CC genotype significantly increased odds of PCa (P=0.007, OR=1.79, 95% C.I.: 1.17-2.75), but not AA men with high vitamin intake (≥400 IU/day). The interaction between TaqI genotypes and vitamin D intake was significant (P=0.01). The TaqI CT/CC genotype significantly increased odds of PCa among AA men who have smoked or with darker skin pigmentation (P&lt;0.05), but not among AA men who never smoked or with lighter skin pigmentation. On the other hand, the TaqI C allele reduced odds of PCa among EA men with biological factors that decrease serum vitamin D levels. The TaqI CT/CC genotype significantly reduced odds of PCa among obese (BMI≥30) or darker pigmented men (P&lt;0.05), but not among lean or lighter pigmented men. The interaction between BMI and TaqI genotypes in EA men was significant (P=0.05).

Conclusion: Although a larger sample size is necessary to confirm our observations, our results suggest that the VDR gene is involved in PCa pathogenesis and progression, but the effects of VDR gene on PCa are modified by behavioral and biological factors that modify serum vitamin D levels.

Citation Format: Ken Batai, Adam B. Murphy, Ebony Shah, Rick A. Kittles. Effect modifiers of vitamin D receptor common polymorphisms on prostate cancer risk. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr B39.